'unshackle' originates from Middle English, specifically the word 'schakelen,' where 'un-' meant 'not' and 'shackle' meant 'to bind or restrain.'

'schakelen' transformed into the modern English word 'shackle,' and with the prefix 'un-' added, it became 'unshackle.'

Initially, it meant 'to remove chains or restraints,' and this meaning has largely remained the same in modern usage.